Secret Diagram

LED Matrix Horizontally The circuit in this Design Idea shows an unconventional way to use a 5×7 LED matrix.You can use a design containing a set of 5×7 LED units without changing anything in the circuitry, except for the arrangement of the LED units. 

LED Matrix Horizontally Circuit Diagram
 

 Using one 5×7 LED matrix, or N units, horizontally instead of vertically allows the display of two characters, or 2×N characters. The minimum pattern for lowercase and uppercase letters requires only a 3×5 LED configuration, except for the letters M and m, which require at least a 5×5 LED configuration and need a dedicated subroutine.

The circuit in Figure 1 uses an 8-bit, 18-pin PIC microcontroller and a decade counter to drive one or two 5×7 LED units to provide a display module of two or four digits. The circuit uses a small pushbutton switch to increment the counter. By default, the circuit works in high-brightness mode. If you press the pushbutton during power-on, the circuit works in low-power mode.